Schipropins A–J, structurally diverse triterpenoids from Schisandra propinqua

Schipropins A–J, a series of undescribed lanostane and cycloartane-type triterpenoids, were isolated from the stems and leaves of Schisandra propinqua. Their structures, most of which were characterized by C-3/C-4 cleavage, were elucidated by extensive spectroscopic analyses. Noteworthily, the absolute configurations of schipropins A, D–G, and I were determined by single-crystal X-ray diffraction. Furthermore, schipropins E and G were found to possess moderate NO production inhibitory activity.